In the related art, an imaging apparatus for diagnosis that generates a tomographic image is widely used for arteriosclerosis diagnosis, for surgery diagnosis at the time of treatment in a blood vessel by a high-performance catheter such as a balloon catheter, or stent, or for confirmation of a surgery result. As an imaging apparatus for diagnosis described above, an ultrasonic diagnostic apparatus (Intra Vascular Ultra Sound: IVUS), an optical interference tomography diagnostic apparatus (Optical Coherence Tomography: OCT), or the like is used in the blood vessel, and the apparatuses have characteristics different from each other.
Recently an imaging apparatus for diagnosis combining the IVUS function and the OCT function has been suggested (For example, see Japanese Patent Application Publication No. 11-56752 and Japanese Patent Application Publication No. 2002-153472). The imaging apparatus for diagnosis described above can generate a tomographic image that encourages both of the characteristic of the IVUS that can measure a high depth region and the characteristic of the OCT that can measure an area at a high resolution. By encouraging advantages of both of the IVUS and the OCT, it is possible to effectively observe a state of, for example, a plaque or the like.